/Engine/Source/Runtime/CoreUObject/Public/UObject/PackageTrailer.h
Adds an already virtualized payload to the builder to be written to the trailer. When the trailer is written the payload will haveEPayloadAccessMode::Virtualizedset as it's access mode. It is assumed that the payload is already stored in the virtualization backends and it is up to the calling code to confirm this. Duplicate payloads will be discarded and only a single instance stored in the trailer.
void AddVirtualizedPayload ( const [FIoHash](API\Runtime\Core\IO\FIoHash) & Identifier, int64 RawSize )